Rake classifier



April 25, 1939. D. M. WRIGHT RAKE CLASSIFIER Filed Nov. 25, 1936 INVENTOR A TTE$T- $674M ATTORNE Patented Apr. 25, 1939 RAKE CLAS SIFIER David M. Wright, Agricola, Fla., assignor to Industrial Patents Corporation, Chicago, 111., a corporation of Delaware Application November 23, 1936, Serial No. 112,408

2 Claims. (Cl. 209-462) the pin 23. The lever arm 22 is pivoted on the ed at opposite ends of the trough, a link connectshaft 24, which is fixed in position as by keepers ing said levers, links connecting said levers with 25 and 39. Rod I9 is pivoted on pin 20 which is said rake, a toggle link pivotally secured at one held in fixed position as by keeper 26. of its ends at a fixed point and at its opposite The motion of the rod I6 by the crank pin l3 end to one of said levers, said toggle link being causes an alternate lengthening nd ho ening adapted for pivotal movement at substantially of the distance between pins 20 and 23, thus givthe center thereof, a rotatable shaft, a crank ing motion to the lever arm 22, and alternately means rigidly secured at one of its ends to said raising and lowering the rake. The raising and shaft, a link connecting said crank means with lowering is accomplished by reason of the resultsaid toggle link at the substantially central pivot ant rise and fall of pins 21 and 28. The rod 29 thereof and a link connecting said crank means is pivoted to lever arm 22 by pin 2'! and to plate with said rake. 8 by pin 30. The motion of lever arm 22 is com- 2. In a classifying rake having a relatively long, municated to lever arm 3| by rod 32, pivoted to substantially flat operating zone, a drive shaft lever arm 22 by pin 33 and to lever arm 3| by provided with a crank means, a rod operatively pin 4. Ro 35 i p v e o lever arm 3| by connected with the crank means and with the pin 28 and to plate 9 by pin 35. Lever arm 3| is rake in a manner to impart backward and forpivoted on fixed shaft 31. Shaft I0, which operward movement to the rake, bell cranks operaates crank II, is fixed by bearing 38 and receives tively connected with one another and with the power from a source not shown. rake, and means including a toggle link opera- In the embodiments shown in the drawing, tively connected with one of the bell cranks in a shaft 24 extends entirely across the device and manner to raise and lower the rake, the toggle is held in keepers 25 and d la y S af link comprising two pivoted arms, one arm at its 31 extends across the device and is held in keepers free end being separately pivoted at a fixed point, r 40 and 4|. Lever arms 22 and 3 re rigidly the other arm at its free end being separately affix d to Shafts and resp ively, as by pivoted to one of the bell cranks, and a rod operk y e, wh y the tativ motion f shafts 4 atively connected with the central pivot of the and 31 may be communicated to duplicate lever two arms and with the crank means, the lastarm a d r d mechanism for raising d lowermentioned rod being of a length such that at the 55 ing the a e On the pposite side of the device central point of the forward stroke of the rod the This invention relates to ore conveyors and classifiers.

One of the objects of the invention is to provide a classifying rake which gives a long, substantially fiat operating zone.

Other objects of the invention will be apparent from the description and claims which follow.

A preferred embodiment of the invention is shown in the drawing.

Figure 1 is a side view, partly in section.

Figure 2 is a plan view of the device shown in Figure 1. The cross pieces I of rake 2 operate on inclined bed 3 of trough 4. Cross pieces I which may be made of channel iron or angle iron are rigidly affixed to frame 5 of rake 2. Plates 6, I, 8, and 9 are rigidly afilx'ed to frame 5. The mechanism for dragging the rake upwardly on the bed, lifting it and returning it to repeat the cycle, is operated by shaft l0 through the cranks H and I2 and the crank pins l3 and M.

The lateral motion of the rake is governed by crank pin l4 through the rod l5. Crank pin l3 operates the rod IE to the toggle ll, consisting of the rods 18 and I9 and the pins 29 and 2|.

Rod I8 is connected to the lever arm 22 by and operatively connected with plates 6 and 1.

It will be seen that the rake is lowered on the forward motion to the left and raised on the backward motion to the right. To flatten the curve of the forward motion of the rake, it is necessary that the pivot 21 from which the rake is suspended shall be in a higher position in the center of the forward stroke than at the ends of the useful stroke. This is accomplished by having the rod l6 of such length that at the central point of the forward stroke, as shown in the drawing, the pin 2| will be at a point beyond a straight line from pins 23 to 20. In the drawing this is shown to be to the right of the line. This i results in shortening the distance between 23 and 20 and raising the pivot 27. It will be clear that the pivot 28 is in operative synchronism with pivot 21.

It will be seen that the toggle link arrangement employed in the present invention provides a novel means for securing a relatively long, substantially fiat operating zone, increasing the conveying efficiency and dewatering effectiveness of the rake.

I claim:

1. In an ore conveyor and classifier comprising a trough and a rake having a relatively long, substantially flat operating zone reciprocally mounted in said trough, bell crank levers mountcentral pivot is at a point beyond a straight line between the first pivot and the bell crank pivot.

DAVID M. WRIGHT. 

